diamonds 101

all diagrams courtesy of the GIA

four Cs: Carat


okay, so we spend a TON of time talking about what kind of diamonds make up all this royal gear, but how many of you can tell an Old European cut from a Cushion cut? Does it even mean anything?

basic diagram of diamond cuts

Asscher Cut — named for the Dutch brothers Asscher who cut the famous 3,106 -carat  Cullinan. The modern asscher is similar to a square emerald cut, usually  with larger step facets, a higher crown and a smaller table. As a result, it is more brilliant than the Emerald cut. An asscher will appear to have concentric squares as you look down through the table.

Brilliant Cut – diamonds, usually circular, with 58 facets, cut in a pattern perfected in 1920.

Cushion Cut [I’ve heard this also described as a Miners Cut too] combines a square cut with rounded corners and curved sides, much like a pillow. See now you’re catching on…they have a softer look than a Princess Cut but not as circular as a round stone.

Emerald Cut —Rectangular stone with chamfered corners—read octagonal in outline—faceted sloping sides and a flat top or table.

European Cut—the most popular diamond cut used from the 1890s through the 1920s. Round in shape, they have open culets with smaller tables and deeper pavilions than the modern round-cut brilliant.

Heart-Cut — another modification of the brilliant cut. Like the Marquise, the symmetry and proportions of the cut are imperative. The shape itself is hard to detect on a stone smaller than a half-carat.

Marquise — Named for la Marquise de Pompadour, a football-shaped modified version of the brilliant cut. As a result of its elongated shape, it can make the stone seem larger, or your fingers longer and thinner. Me and my fat fingers, huh.

Miners’ Cut – 19th Century Method of faceting gemstones—usually diamonds—that lasted until the early 1900s. These diamonds have fewer facets so they twinkle with a subtle sparkle rather than the fiery flash of their modern counterparts.

Oval Cut — invented in the 60s by Lazare Kaplan, this is another modification of the brilliant-cut. The two shapes possess the same fire and brilliance.

Peardrop (or Teardrop) Cut —the traditional variety of the fancy brilliant cut diamond but in the shape of a pear.

Princess Cut— typically square or near square in shape, it has a lower price-per-carat than round cut diamonds. This is because the four sided pyramid shape of the princess cut diamond is similar to one half of the octahedron rough stone from which a princess diamond is cut. This similarity allows two equally sized princess cut diamonds to be cut from the same rough stone with relatively little waste (roughly 60% of the weight of the original rough stone is retained after cutting).

Radiant Cut – the first square cut to have a complete brilliant-cut facet pattern applied to both the crown and the pavilion to maximize vibrance and fire. First became popular in the 1980s. The cropped corner square shape of the radiant makes a nice halfway point between cushion and a princess cut.  As a result they look good next to both round and square stones.

Rose — A diamond with 24 facets and a flat base rising to a point; this style is normally reserved for smaller stones.

Trapeze — A step-cut or emerald-cut stone in trapezoid form


GIA diamond color grading


GIA diamond clarity diagram